Targeted folate-conjugated pluronic P85/poly(lactide-co-glycolide) polymersome for the oral delivery of insulin

Dual-Responsive Nanogels with Cascaded Gentamicin Release and Lysosomal Escape to Combat Intracellular Small Colony Variants for Peritonitis and Sepsis Therapies

Intracellular bacteria are the major cause of serious infections including sepsis and peritonitis, but face great challenges in fighting against the stubborn intracellular small colony variants (SCVs). Herein, the authors have developed nanogels (NGs) to destroy both planktonic bacteria and SCVs and eliminate excessive inflammations for peritonitis and sepsis therapies. Free gentamicin (GEN) and hydroxyapatite nanoparticles (NPs) with GEN loading and mannose grafts (mHAG) are inoculated into ε-polylysine NGs to obtain NG@G1-mHAG2 through crosslinking with phenylboronic acid and tannic acid. The H2O2 consumption after reaction with phenylboronic esters and the elimination of free radicals by tannic acid alleviates the escalated inflammatory status to promote sepsis therapy. After mannose-mediated uptake into macrophages, the acid-triggered degradation of mHAG NPs generates Ca2+ to destabilize lysosomes and the efficient lysosomal escape leads to reversion of hypometabolic SCVs into normal phenotype and their sensitivity to GEN. In a peritonitis mouse model, NG@G1-mHAG2 treatment provides strong and persistent bactericidal effects against both extracellular bacteria and intracellular SCVs and extends survival of peritonitis mice without apparent hepatomegaly, splenomegaly, pulmonary edema, and inflammatory cell infiltration. Thus, this study demonstrates a concise and versatile strategy to eliminate SCVs and relieve inflammatory storms for peritonitis and sepsis therapies without infection recurrence.

Quality by design (QbD) approach-based development of optimized nanocarrier to achieve quality target product profile (QTPP)-targeted lymphatic delivery

Background.Insulin, commonly used for diabetes treatment, needs better ways to improve its effectiveness and safety due to its challenges with poor permeability and stability. Various system has been developed for oral peptide delivery. The non-targeted system can prevent gastric and enzymatic degradation of peptides but cannot increase the bulk transport of peptides across the membrane. However, the non-selectivity is the limitation of the existing system. Numerous carbohydrate-binding receptors overexpressed on intestinal macrophage cells (M-cells) of gut-associated lymphoid tissue. It is the most desirable site for receptor-mediated endocytosis and lymphatic drug delivery of peptides.Objective. The prime objective of the study was to fabricate mannose ligand conjugated nanoparticles (MNPs) employing a quality-by-design approach to address permeability challenges after oral administration. Herein, the study's secondary objective of this study is to identify the influencing factor for producing quality products. Considering this objective, the Lymphatic uptake of NPs was selected as a quality target product profile (QTPP), and a systematic study was conducted to identify the critical formulation attributes (CFAs) and critical process parameters (CPP) influencing critical quality attributes (CQAs). Mannosylated Chitosan concentrations (MCs) and TPP concentrations were identified as CFAs, and stirring speed was identified as CPP.Methods. MNPs were prepared by the inotropic gelation method and filled into the enteric-coated capsule to protect from acidic environments. The effect of CFAs and CPP on responses like particle size (X) and entrapment (Y) was observed by Box-Behnken design (BBD). ANOVA statistically evaluated the result to confirm a significant level (p< 0.05). The optimal conditions of NPs were obtained by constructing an overlay plot and determining the desirability value. HPLC and zeta-seizer analysis characterized the lyophilized NPs. Cell-line studies were performed to confirm the safety and M-cell targeting of NPs to enhance Insulin oral bioavailability.Results. The morphology of NPs was revealed by SEM. The developed NPs showed a nearly oval shape with the average size, surface potential, and % drug entrapment were 245.52 ± 3.37 nm, 22.12 ± 2.13 mV, and 76.15 ± 1.3%, respectively. MTT assay result exhibited that MNPs safe and Confocal imaging inference that NPs selectively uptake by the M-cell.Conclusion. BBD experimental design enables the effective formulation of optimized NPs. The statistical analysis estimated a clear assessment of the significance of the process and formulation variable. Cell line study confirms that NPs are safe and effectively uptake by the cell.

FAP Targeting of Photosensitizer-Loaded Polymersomes for Increased Light-Activated Cell Killing

As current chemo- and photodynamic cancer therapies are associated with severe side effects due to a lack of specificity and to systemic toxicity, innovative solutions in terms of targeting and controlled functionality are in high demand. Here, we present the development of a polymersome nanocarrier equipped with targeting molecules and loaded with photosensitizers for efficient uptake and light-activated cell killing. Polymersomes were self-assembled in the presence of photosensitizers from a mixture of nonfunctionalized and functionalized PDMS-b-PMOXA diblock copolymers, the latter designed for coupling with targeting ligands. By encapsulation inside the polymersomes, the photosensitizer Rose Bengal was protected, and its uptake into cells was mediated by the nanocarrier. Inhibitor of fibroblast activation protein α (FAPi), a ligand for FAP, was attached to the polymersomes' surface and improved their uptake in MCF-7 breast cancer cells expressing relatively high levels of FAP on their surface. Once internalized by MCF-7, irradiation of Rose Bengal-loaded FAPi-polymersomes generated reactive oxygen species at levels high enough to induce cell death. By combining photosensitizer encapsulation and specific targeting, polymersomes represent ideal candidates as therapeutic nanocarriers in cancer treatment.

Oral Insulin Delivery: A Review on Recent Advancements and Novel Strategies

BACKGROUND

Due to the lifestyle of people in the community in recent years, the prevalence of diabetes mellitus has increased, so New drugs and related treatments are also being developed.

INTRODUCTION

One of the essential treatments for diabetes today is injectable insulin forms, which have their problems and limitations, such as invasive and less admission of patients and high cost of production. According to the mentioned issues, Theoretically, Oral insulin forms can solve many problems of injectable forms.

METHODS

Many efforts have been made to design and introduce Oral delivery systems of insulin, such as lipid-based, synthetic polymer-based, and polysaccharide-based nano/microparticle formulations. The present study reviewed these novel formulations and strategies in the past five years and checked their properties and results.

RESULTS

According to peer-reviewed research, insulin-transporting particles may preserve insulin in the acidic and enzymatic medium and decrease peptide degradation; in fact, they could deliver appropriate insulin levels to the intestinal environment and then to blood. Some of the studied systems increase the permeability of insulin to the absorption membrane in cellular models. In most investigations, in vivo results revealed a lower ability of formulations to reduce BGL than subcutaneous form, despite promising results in in vitro and stability testing.

CONCLUSION

Although taking insulin orally currently seems unfeasible, future systems may be able to overcome mentioned obstacles, making oral insulin delivery feasible and producing acceptable bioavailability and treatment effects in comparison to injection forms.

Size-tunable nanogels for cascaded release of metronidazole and chemotherapeutic agents to combat Fusobacterium nucleatum-infected colorectal cancer

Bacteria play important roles in tumor formation, growth and metastasis through downregulating immune response and initiating drug resistance. Herein, size-tunable nanogels (NGs) have been developed to address the existing size paradox in tumor accumulation, intratumoral penetration and intracellular release of therapeutics for the treatment of Fusobacterium nucleatum (F. nucleatum)-infected colorectal cancer. Zinc-imidazolate frameworks with doxorubicin (DOX) loading and folate grafting (f-ZIFD) were mixed with metronidazole (MET) and encapsulated in NGs through thiol-ene click crosslinking of sulfhydryl hyaluronan, sulfhydryl alginate and 4-arm poly(ethylene glycol) acrylate. Hyaluronidase-initiated matrix degradation causes NG swelling to release sufficient MET and maintains a large size for an extended time period, and the gradually discharged f-ZIFD nanoparticles (NPs) from NGs exhibit acid-responsive intracellular release of DOX after folate-mediated internalization into tumor cells. The encapsulation into NGs significantly enhances the bioavailability and increases half-lives of MET and DOX by around 20 times. In the F. nucleatum-infected tumor model, the extended retention of swollen NGs and the efficient tumor infiltration and cellular uptake of the discharged f-ZIFD NPs cause 6 times higher DOX levels in tumors than that of free DOX administration. F. nucleatum promotes tumor cell proliferation and tumor growth, and the cascaded releases of MET and f-ZIFD NPs eliminate F. nucleatum to effectively inhibit tumor growth with a significant extension of animal survival. Thus, the hyaluronidase-mediated NG expansion and dual-responsive cascaded drug release have overcome challenges in the release regimen and size paradox of drug delivery carriers to combat bacteria-infected cancer.

Mechanisms of Nanoparticle Transport across Intestinal Tissue: An Oral Delivery Perspective

Oral drug administration has been a popular choice due to patient compliance and limited clinical resources. Orally delivered drugs must circumvent the harsh gastrointestinal (GI) environment to effectively enter the systemic circulation. The GI tract has a number of structural and physiological barriers that limit drug bioavailability including mucus, the tightly regulated epithelial layer, immune cells, and associated vasculature. Nanoparticles have been used to enhance oral bioavailability of drugs, as they can act as a shield to the harsh GI environment and prevent early degradation while also increasing uptake and transport of drugs across the intestinal epithelium. Evidence suggests that different nanoparticle formulations may be transported via different intracellular mechanisms to cross the intestinal epithelium. Despite the existence of a significant body of work on intestinal transport of nanoparticles, many key questions remain: What causes the poor bioavailability of the oral drugs? What factors contribute to the ability of a nanoparticle to cross different intestinal barriers? Do nanoparticle properties such as size and charge influence the type of endocytic pathways taken? In this Review, we summarize the different components of intestinal barriers and the types of nanoparticles developed for oral delivery. In particular, we focus on the various intracellular pathways used in nanoparticle internalization and nanoparticle or cargo translocation across the epithelium. Understanding the gut barrier, nanoparticle characteristics, and transport pathways may lead to the development of more therapeutically useful nanoparticles as drug carriers.

The crossroad of nanovesicles and oral delivery of insulin

INTRODUCTION

Diabetes mellitus is one of the challenging health problems worldwide. Multiple daily subcutaneous injection of insulin causes poor compliance in patients. Development of efficient oral formulations to improve the quality of life of such patients has been an important goal in pharmaceutical industry. However, due to serious issues such as low bioavailability and instability, it has not been achieved yet.

AREAS COVERED

Due to functional properties of the vesicles and the fact that hepatic-directed vesicles of insulin could reach the clinical phases, we focused on three main vesicular delivery systems for oral delivery of insulin: liposomes, niosomes, and polymersomes. Recent papers were thoroughly discussed to provide a broad overview of such oral delivery systems.

EXPERT OPINION

Although conventional liposomes are unstable in the presence of bile salts, their further modifications such as surface coating could increase their stability in the GI tract. Bilosomes showed good flexibility and stability in GI fluids. Also, niosomes were stable, but they could not induce significant hypoglycemia in animal studies. Although polymersomes were effective, they are expensive and there are some issues about their safety and industrial scale-up. Also, we believe that other modifications such as addition of a targeting agent or surface coating of the vesicles could significantly increase the bioavailability of insulin-loaded vesicles.

Research Progress on the Mechanism of Nanoparticles Crossing the Intestinal Epithelial Cell Membrane

Improving the stability of drugs in the gastrointestinal tract and their penetration ability in the mucosal layer by implementing a nanoparticle delivery strategy is currently a research focus in the pharmaceutical field. However, for most drugs, nanoparticles failed in enhancing their oral absorption on a large scale (4 folds or above), which hinders their clinical application. Recently, several researchers have proved that the intestinal epithelial cell membrane crossing behaviors of nanoparticles deeply influenced their oral absorption, and relevant reviews were rare. In this paper, we systematically review the behaviors of nanoparticles in the intestinal epithelial cell membrane and mainly focus on their intracellular mechanism. The three key complex intracellular processes of nanoparticles are described: uptake by intestinal epithelial cells on the apical side, intracellular transport and basal side exocytosis. We believe that this review will help scientists understand the in vivo performance of nanoparticles in the intestinal epithelial cell membrane and assist in the design of novel strategies for further improving the bioavailability of nanoparticles.

Progress in oral insulin delivery by PLGA nanoparticles for the management of diabetes

Currently, the only practical way to treat type 1 and advanced insulin-dependent type 2 diabetes mellitus (T1/2DM) is the frequent subcutaneous injection of insulin, which is significantly different physiologically from endogenous insulin secretion from pancreatic islets and can lead to hyperinsulinemia, pain, and infection in patients with poor compliance. Hence, oral insulin delivery has been actively pursued to revolutionize the treatment of insulin-dependent diabetes. In this review, we provide an overview of recent progress in developing poly(lactic co-glycolic acid) (PLGA) nanoparticles (NPs) for oral insulin delivery. Different strategies for insulin-loaded PLGA NPs to achieve normoglycemic effects are discussed. Finally, challenges and future perspectives of PLGA NPs for oral insulin delivery are put forward.

Ligand-modified nanocarriers for oral drug delivery: Challenges, rational design, and applications

Ligand-modified nanocarriers (LMNCs) specific to their targets have attracted increasing interest for enhanced oral drug delivery in recent decades. Although the design of LMNCs for enhanced endocytosis and improved exposure of the loaded drugs through the oral route has received abundant attention, it remains unclear how the design influences their transcellular process, especially the key factors affecting their functions. This review discusses the extracellular and cellular barriers to orally administered LMNCs in the gastrointestinal (GI) tract and new discoveries regarding the GI protein corona and the sequential transport barriers that impede the preplanned movements of LMNCs after oral administration. Furthermore, innovative progress in considering key factors (including target selection, ligand properties, and other important factors) in the rational design of LMNCs for oral drug delivery is presented. In particular, some factors that endow LMNCs with efficient transcytosis rather than only endocytosis are highlighted. Finally, the prospects of orally administered LMNCs in disease therapy for the enhanced oral/local bioavailability of active pharmaceutical ingredients, as well as emerging delivery routes, such as lymphatic drug delivery and systemic location-specific drug release based on oral transcellular LMNCs, are discussed.

Self-Propelling Nanomotors Integrated with Biofilm Microenvironment-Activated NO Release to Accelerate Healing of Bacteria-Infected Diabetic Wounds

Diabetic foot ulcer (DFU) treatment is challenged by persistent bacterial infection and hyperglycemia-caused vascular dysplasia. Herein, self-propelled nanomotors are designed to achieve biofilm microenvironment (BME)-activated multistage release of NO for effective sterilization and subsequent angiogenesis promotion. CaO₂ nanoparticles (NPs) are capped with PDA layers, followed by complexation with Fe²⁺ and surface grafting of cysteine-NO to obtain Janus Ca@PDA_Fe -CNO NPs. In response to low pH in BME, the decomposition of CaO₂ cores generates O₂ from one side of Janus NPs to propel biofilm penetration, and the released H₂ O₂ and Fe²⁺ produce •OH through Fenton reaction. The concurrent glutathione-triggered release of NO can be converted into reactive nitrogen species, which exhibit significantly higher bactericidal efficacy than those with only generation of •OH or NO. The slow release of NO for an extended time period promotes endothelial cell proliferation and migration. On Staphylococcus aureus-infected skin wounds of diabetic mice, NP treatment eliminates bacterial infections and significantly elevates blood vessel densities, leading to full wound recovery and regeneration of arranged collagen fibers and skin accessories. Thus, the self-propelling and multistage release of NO provide a feasible strategy to combat biofilm infection without using any antibiotics and accelerate angiogenesis and wound healing for DFU treatment.

Transferrin/folate dual-targeting Pluronic F127/poly(lactic acid) polymersomes for effective anticancer drug delivery

A novel dual-targeting Pluronic/poly(lactic acid) polymersome containing transferrin and folic acid ligands (Tf/FA-F127-PLA) has been designed to study its application in the targeted drug delivery system. Both biotin and folic acid conjugated Biotin/FA-F127-PLA polymersomes (Ps) were prepared as the precursor. The dual-targeting behaviors of Tf/FA-F127-PLA over C6 glioma cells were then fulfilled through connecting the precursor with biotinylated transferrin by using a three-step biotin-avidin technique. Paclitaxel (PTX) was loaded successfully into Biotin/FA-F127-PLA and showed a burst release followed by a slow-release process in vitro. It was also obtained that Tf/FA-F127-PLA had higher cytotoxicity and cellular uptake amount than non-targeted and single-targeted Ps did. These results could be because more PTX-loaded Tf/FA-F127-PLA Ps entered C6 cells through both FA-folate receptor (FR) and Tf-transferrin receptor (TfR) specific affinity and thus possessed the better anti-tumor ability. It was further proved that the uptake of Ps by C6 cells was through the endocytosis related to clathrin, caveolae, lysosome, etc. Furthermore, it was demonstrated that the uptake of dual-targeting Tf/FA-F127-PLA Ps by C6 cells was related to the endocytosis mediated by both FR and TfR. These findings indicated that dual-targeting Tf/FA-F127-PLA Ps could be a potential carrier in targeted drug delivery systems.

Recent Advancement of Polymersomes as Drug Delivery Carrier

BACKGROUND

Biomedical applications of polymersomes have been explored, including drug and gene delivery, insulin delivery, hemoglobin delivery, the delivery of anticancer agents, and various diagnostic purposes.

OBJECTIVES

Polymersomes, which are self-assembled amphiphilic block copolymers, have received a lot of attention in drug delivery approaches. This review represents the methods of preparation of polymersomes including thin-film rehydration, electroformation, double emulsion, gel-assisted rehydration, PAPYRUS method, and solvent injection methods including various therapeutic applications of polymersomes.

METHODS

Data we searched from PubMed, Google Scholar, and Science Direct through searching of keywords: Polymersomes, methods of preparation, amphiphilic block copolymers, anticancer drug delivery Results: Polymersomes provide both hydrophilic and hydrophobic drug delivery to a targeted site with an increase in the stability of the formulation and reduce the cytotoxic side effects of drugs.

CONCLUSION

A wide range of biological applications, including drug and gene delivery, insulin delivery, hemoglobin delivery, delivery of anticancer agents as well as in various diagnostic purposes. Recently, polymersomes have been used more frequently because of their stability, reducing the encapsulated drug's leakage, site-specific drug delivery, and increasing the bioavailability of the drugs and different diagnostic purposes. The liposomes encapsulate only hydrophilic drugs, but polymersomes encapsulate both hydrophilic and hydrophobic drugs in their cores.

Advances in the therapeutic delivery and applications of functionalized Pluronics: A critical review

Pluronic (PEO-PPO-PEO) block copolymers can form nano-sized micelles with a structure composed of a hydrophobic PPO core and hydrophilic PEO shell layer. Pluronics are U.S. Food and Drug Administration approved polymers, which are widely used for solubilization of drugs and their delivery, gene/therapeutic delivery, diagnostics, and tissue engineering applications due to their non-ionic properties, non-toxicity, micelle forming ability, excellent biocompatibility and biodegradability. Although Pluronics have been employed as drug carrier systems for several decades, numerous issues such as rapid dissolution, shorter residence time in biological media, fast clearance and weak mechanical strength have hindered their efficacy. Pluronics have been functionalized with pH-sensitive, biological-responsive moieties, antibodies, aptamers, folic acid, drugs, different nanoparticles, and photo/thermo-responsive hydrogels. These functionalization strategies enable Pluronics to act as stimuli responsive and targeted drug delivery vehicles. Moreover, Pluronics have emerged in nano-emulsion formulations and have been utilized to improve the properties of cubosomes, dendrimers and nano-sheets, including their biocompatibility and aqueous solubility. Functionalization of Pluronics results in the significant improvement of target specificity, loading capacity, biocompatibility of nanoparticles and stimuli responsive hydrogels for the promising delivery of a range of drugs. Therefore, this review presents an overview of all advancements (from the last 15 years) in functionalized Pluronics, providing a valuable tool for industry and academia in order to optimize their use in drug or therapeutic delivery, in addition to several other biomedical applications.

Physico-chemical and spectroscopic investigation of flavonoid dispersed C n TAB micelles

In this study, kaempferol (0.2 m/mmol kg-1) dispersed cationic surfactant micelles were prepared as a function of alkyltrimethylammonium bromide (C n TAB) hydrophobicity (C = 12 to C = 16). The dispersion study of kaempferol in different C n TAB, i.e. dodecyltrimethylammonium bromide (C = 12), tetradecyltrimethylammonium bromide (C = 14) and hexadecyltrimethylammonium bromide (C = 16), was conducted with the physico-chemical properties of density, sound velocity, viscosity, surface tension, isentropic compressibility, acoustic impedance, surface excess concentration and area occupied per molecule and thermodynamic parameters Gibbs free energy, enthalpy and activation energy measured at 298.15 K. These properties were measured with varying concentration of C n TAB from 0.0260 to 0.0305 mol kg-1 in a 10% (w/w) aqueous dimethyl sulfoxide solvent system. The variations in these measured properties have been used to infer the kaempferol dispersion stability via hydrophobic-hydrophilic, hydrophilic-hydrophilic, van der Waals, hydrogen bonding and other non-covalent interactions.

Novel strategies to oral delivery of insulin: Current progress of nanocarriers for diabetes management

Diabetes mellitus is one of the most serious public health problems in the world. Repeated daily injections of subcutaneous insulin is the standard treatment for patients with type 1 diabetes mellitus; however, subcutaneous insulin injections can potentially cause local discomfort, patient noncompliance, hypoglycemia, failure to regulate glucose homeostasis, infections, and fat deposits at the injection sites. In recent years, numerous attempts have been made to produce safe and efficient nanoparticles for oral insulin delivery. Oral administration is considered the most effective alternative route to insulin injection, but it is accompanied by several challenges related to enzymatic proteolysis, digestive breakdown, and absorption barriers. A number of natural and synthetic polymeric, lipid-based, and inorganic nanoparticles have been investigated for use. Although improvements have recently been made in potential oral insulin delivery systems, these require further investigation before clinical trials are conducted. In this review, new approaches to oral insulin delivery for diabetes treatment are discussed, including polymeric, lipid-based, and inorganic nanoparticles, as well as the clinical trials performed for this purpose.

Oral delivery of proteins and peptides: Challenges, status quo and future perspectives

Proteins and peptides (PPs) have gradually become more attractive therapeutic molecules than small molecular drugs due to their high selectivity and efficacy, but fewer side effects. Owing to the poor stability and limited permeability through gastrointestinal (GI) tract and epithelia, the therapeutic PPs are usually administered by parenteral route. Given the big demand for oral administration in clinical use, a variety of researches focused on developing new technologies to overcome GI barriers of PPs, such as enteric coating, enzyme inhibitors, permeation enhancers, nanoparticles, as well as intestinal microdevices. Some new technologies have been developed under clinical trials and even on the market. This review summarizes the history, the physiological barriers and the overcoming approaches, current clinical and preclinical technologies, and future prospects of oral delivery of PPs.

Design of folic acid decorated virus-mimicking nanoparticles for enhanced oral insulin delivery

Mucus penetration and intestinal cells targeting are two main strategies to improve insulin oral delivery efficiency. However, few studies are available regarding the effectiveness of combining these two strategies into one nano-delivery system. For this objective, the folic acid (FA) decorated virus-mimicking nanoparticles were designed and influence of FA graft ratio on the in vitro and in vivo properties of insulin loaded nanoparticles was studied systemically. Firstly, using folic acid as active ligand, different folic acid grafted chitosan copolymers (FA-CS) were synthesized and characterized. Thereafter, using insulin-loaded poly(n-butylcyanoacrylate) nanoparticles as the core, virus-mimicking nanoparticles were fabricated by coating of positively charged FA-CS copolymer and negatively charged hyaluronic acid. Irrespective of the FA graft ratio, all the nanoparticles showed good stability, similar insulin release in the gastrointestinal fluid, excellent and similar penetration in mucus. The nanoparticles permeability in intestine was FA graft ratio and segment dependent, with FA graft ratio at/over 12.51% presenting better effect in the order of duodenum > jejunum ≈ ileum. Both mechanism studies and confocal microscopy observation demonstrated FA-mediated process was involved in the transport of FA decorated nanoparticles. In vivo studies revealed hypoglycemic effect of the nanoparticles was FA graft ratio dependent, a saturation phenomenon was observed when FA graft ratio was at/over 12.51%. In conclusion, folic acid decorated virus-mimicking nanoparticles presented improved insulin absorption, implying combining mucus penetration and active transcellular transport is an effective way to promote oral insulin absorption, while the modification ratio of active ligand needs optimization.

Study on the Influencing Factors of Hypoglycemic Effect of Folate Targeted Polymersomes Encapsulating Insulin

PURPOSE

To study the effects of the density of folic acid (FA) on the hypoglycemic ability of FA-targeted polymersomes as oral insulin carriers. Also to study the change of the hypoglycemic effect of FA-targeted mixed polymersomes added with various mass ratio of d-α-tocopherol polyethylene glycol 1000 succinate (TPGS).

METHODS

The FA-targeted polymersomes with different FA molar contents were prepared. The in vitro insulin release experiments in different media for FA-targeted polymersomes with various FA contents were studied. Their quantitative cellular uptake in Caco-2 cells was examined. The in vivo hypoglycemic activity of FA-targeted polymersomes was also studied with diabetic rats. The polymersomes with the optimal FA molar content was chosen to prepare mixed polymersomes with various TPGS contents.

RESULTS

Among insulin-loaded FA-targeted polymersomes with four different FA molar contents, insulin-loaded polymersomes with 10% FA molar content (insulin-loaded 10%FA-Ps) showed the hightest cellular uptake and the best hypoglycemic response. In addition, the insulin-loaded FA-Ps/TPGS5:1 mixed polymersomes exhibited higher cellular uptake and better hypoglycemic response than the other two insulin-loaded mixed polymersomes adding TPGS did.

CONCLUSIONS

FA-Ps/TPGS5:1 could be a promising formulation for the oral administration of insulin.

Oral delivery of folate-targeted resveratrol-loaded nanoparticles for inflammatory bowel disease therapy in rats

AIMS

In the current study, resveratrol-loaded PLGA nanoparticles targeted with folate were developed in order to protect resveratrol from fast degradation, modify its pharmacokinetics and increase its intestinal permeation. Then, the therapeutic efficacy of the prepared system was evaluated in suppression of colon inflammation on TNBS-induced colitis model.

MAIN METHODS

In this regard, resveratrol was encapsulated in PLGA and FA-conjugated PLGA in order to prepare non-targeted (PLGA-RSV) and targeted (PLGA-FA-RSV) platforms, respectively.

KEY FINDINGS

Obtained results demonstrated that the prepared formulations encapsulated the resveratrol with high encapsulation efficiency of 90.7% ± 5.1% for PLGA-RSV and 59.1% ± 3.3% for PLGA-FA-RSV. In vitro release experiment showed that the prepared formulations were capable of retaining good amount of resveratrol under the simulated gastric condition (HCl 0.1 N, pH 1.2), while significant amount of resveratrol was released under simulated intestinal condition (PBS, pH 7.4). The trans-well permeability rates through Caco-2 monolayer during 180 min, was determined to be 4.5%, 61% and 99% for resveratrol, PLGA-RSV and PLGA-FA-RSV respectively. The pathological analysis of the rat intestinal sections (hematoxylin & eosin staining) at 7th day post-TNBS colonic inflammation induction illustrated that the oral administrations of FA-PLGA-RSV and PLGA-RSV were able to significantly inhibit the inflammation and reduce neutrophil and lymphocytes accumulation. It is worth noting that the folate-targeted system demonstrated highest efficacy in suppressing colon inflammation.

SIGNIFICANCE

It could be concluded that the encapsulation of resveratrol into biodegradable folate-targeted PLGA nanoparticles could introduce a potent platform in suppressing colonic inflammation thus offering a great capability for clinical translation.

Novel folated pluronic F127 modified liposomes for delivery of curcumin: preparation, release, and cytotoxicity

Aim: A novel folated pluronic F127 (FA-F127) was synthesised, so as to modify liposomes with FA group on the surface, and evaluate the effects of FA-F127 modification on the properties of the modified liposomes.Methods: FA was linked to one end of pluronic F127, via the terminal OH group, to obtain FA-F127 and the structure was characterised. FA-F127 modified curcumin liposomes (cur-FA-F127-Lps) were prepared. The physicochemical characteristics of cur-FA-F127-Lps, including morphology and particle size, were studied. The in vitro cytotoxicity of cur-FA-F127-Lps against KB cancer cells was determined by MTT tests.Results: The effects of FA-F127 modification on the average particle size, PDI, curcumin encapsulation efficiency and microstructure were not significant. Compared with nonfolated F127 liposomes (cur-F127-Lps), cur-FA-F127-Lps exhibited significantly higher cytotoxicity towards KB cells.Conclusions: Folic acid modified liposomes provide a novel strategy to improve the chemotherapeutic efficacy of hydrophobic bioactive compounds.